The article that follows is the first instalment of “Who Controls the Platform?”—a multi-part Quillette series authored by social-media insiders. Our editors invite submissions to this series, which may be directed to pitch@quillette.com. In late August, I wrote a note to my then-colleagues at Facebook about the issues I saw with political diversity inside the company. You may have read it, because someone leaked the memo to the New York Times, and it spread outward rapidly from there. Since then, a lot has happened, including my departure from Facebook. I never intended my memos to leak publicly—they were written for an internal corporate audience. But now that I’ve left the company, there’s a lot more I can say about how I got involved, how Facebook’s draconian content policy evolved, and what I think should be done to fix it. *     *     * My job at Facebook never had anything to do with politics, speech, or content policy—not officially. I was hired as a software engineer, and I eventually led a number of product teams, …